The type xs:decimal represents a signed decimal number of implementation-defined precision. Numeric literals that contain only digits and a decimal point (no letter E or e) are considered decimal numbers, with the type xs:decimal. For example, 25.5 and 25.0 are xs:decimal values.

The type xs:integer represents a signed integer. The limit on how large an xs:integer value can be is implementation-defined. Numeric literals that contain only digits (no decimal points or the letter E or e) are considered integers, with the type xs:integer. For example, 25 is an xs:integer value.

In the type hierarchy, xs:integer is derived by restriction from xs:decimal. Therefore, anywhere XQuery is expecting an xs:decimal value, an xs:integer value may be used in its place because of subtype substitution.

The type xs:float is patterned after IEEE single-precision 32-bit floating-point numbers, and xs:double is patterned after IEEE double-precision 64-bit floating-point numbers. The representation of both xs:float and xs:double values is a mantissa (a decimal number) followed by the character E or e, followed by an exponent, which must be an integer. For example, 3E2 represents 3 × 10², or 300. Numeric literals that contain an E or e are considered to have the type xs:double.

In addition, the following values are represented: INF (infinity), -INF (negative infinity), and NaN (not a number).